FREQUENCY MODULATED SCREENING METHOD BASED ON THE DUAL FEEDBACK ERROR DIFFUSION

摘要

The present invention discloses a frequency modulated screening method based on the dual feedback error diffusion. This method belongs to the method for generating halftone grid dots in the field of image hard copy. There is a certain technique difficulty in the prior FM and AM screening technology for the output device to output the good quality halftone image grid dots in low resolution, i.e. the satisfactory effect of the reproduction of the layered details in manuscript image as well as the image smoothess can not be achieved. The method of present invention organically combines the FM screening with the AM screening during the net hanging by using the dual feedback technique based on the basic arithmetic of error diffusion so that the effect of hybrid screening is achieved. In the case of the resolution of the output device is low, the method of present invention can solve the problem of easily losing of the layer of grid dots and can reduce the texture due to the random distribution characteristic, thus the richly layered halftone image of good quality can be output.